The transportation industry provides a wide variety of modes and routes with which to meet diverse demands. Selection can be based on numerous factors, including required delivery speed, security and the influence of transportation cost on the price of goods and services. When rapid, time-critical movement is required over a long distance, e.g., thousands of miles, air service has been the norm for both passenger and cargo transport. By way of example, rapid deployment of large military operations can require significant levels of air transport to place equipment and personnel where they are needed when they are needed. On the other hand, when commodity freight is being moved large distances, selection of the transportation mode is more cost sensitive, but often limited by the availability of low-cost choices. Depending on points of departure and destination, multiple low cost choices may be available, but there is often a need to accept the slowest transit speeds to minimize transportation expense and thereby assure cost competitive goods and services. The cost of freight transport is highly dependent on operational costs.
When moving large volumes of freight between different continents, sea transport has been the predominant mode due to cost, while passenger transportation is predominantly by air. Commerce along some large inland waterways may be predominantly by barge or freighter, being limited to commodity products or large cargo which is cost prohibitive or impractical to ship over land. Generally, the choice of water transportation for long distance shipment implies acceptance of relatively slow delivery speed. When multiple transportation modes are available to reach a freight destination the competitiveness of the maritime industry has been challenged. Other modes may be less fuel efficient but are still cost competitive while also providing greater speed and flexibility. For example, the rail and trucking industries are often capable of more quickly delivering products to final destinations while cargo shipped by water must often be transferred to rail cars or trailers to effect final delivery.
In order for transportation by water to be more competitive it would be desirable to improve speed and further reduce transportation costs. However, operating costs, often increase with speed, particularly for freightliners. Such limiting factors are rooted in the limits of achievable hydrodynamic efficiencies for vessel designs. It has long been known that the efficiency of movement through water is a function of a ship's length to beam (L/B) ratio. There have been continual efforts to improve the design of ships with high L/B ratios for operation at relatively high speeds. Several classes of vessels have been so optimized.
Limitations in achievable performance stem from inherent structural issues associated with performance under high structural loads and bending moments such as experienced in high sea states. Strength and flexure issues associated with long, slender ships are addressed with provision of a more robust, typically heavier, longitudinal girder system relative to that required for relatively short ships. Generally, the length of the ship dictates the size and weight of the longitudinal girder system. With advanced analysis capabilities to model behaviors of hulls under dynamic loading, and considering the length of the ship as a single beam for modeling of behavior, girder systems must be of sufficient stiffness and mass to assure acceptable operation in the presence of expected bending moments. It is desirable to develop designs for long and slender vessels (e.g., with L/B>10) which avoid the complexities and added mass conventionally required, as such can enable a more cost efficient ship which can operate more economically. Such improvements can render maritime transportation more suitable for a variety of commerce and non-commercial needs. What is needed is a set of solutions which render maritime operations faster, more flexible, and more cost efficient. With such greater capabilities maritime transportation can be a more acceptable alternative to transportation needs that otherwise must be addressed with air or land-based systems.